Barrier package aerosol containers (“BPA containers”) are used to dispense flowable materials such as processed cheese, frosting, shaving cream, pesticides, paint, and the like. In general, an aerosol container can include a can that contains a flowable product and a propellant. A valve is mounted on one end of the can and is configured to be selectively opened to allow the propellant to drive the flowable product out of the can. In some aerosol containers a piston in the can is used to separates the propellant from the flowable product. The piston moves distally toward the valve as the flowable material is dispensed.